The human cytomegaloviruses (HCMV) are ubiquitous species-specific agents which are capable of producing latent and persistent infections and are associated with numerous diseases including Kaposi's sarcoma. Recently, we found that the HCMV genome strain AD169 contains conserved sequences also present in uninfected cells. One set of sequences is related to human repetitive DNA and maps at the L-S junction of the genome. A second set of sequences shares homology with the cell-derived oncogene myc from the avian retrovirus MC-29. We propose to characterize the molecular organization, origin, and function of the above cell-related sequences in the HCMV genome. In particular, we will analyze by DNA sequencing the structure of these sequences and determine their role in HCMV infections with special emphasis on their relationship to viral gene transcription. We also propose to use our well characterized cloned subgenomic fragements of the HCMV genome as hybridization reagents to analyze the association of HCMV with Kaposi's sarcoma. Preliminary studies in my laboratory indicate that a subset of HCMV sequences are retained in these tumors. Our plan of approach is 1) to identify the regions of HCMV retained in these tumors, 2) to determine whether the HCMV sequences are integrated and if so whether integration is at a unique site in the host cell genome, 3) to characterize any HCMV transcripts in the tumor, and 4) to determine whether the gene(s) responsible for the transformed phenotype of Kaposi tumor cells is dominant and if so, the relationship of this dominant gene to HCMV DNA residing in the tumor. For these studies we will use molecular biological techniques including recombinant DNA technology, nucleic acid hybridization with highly defined reagents, DNA sequencing, in vitro pol III-directed RNA synthesis, and DNA transfection. The long range goals of this research are to define thoroughly the organization and expression of the HCMV genome, to elucidate mechanisms of disease pathogenesis, of latency, and of viral persistence, and to determine the involvement of HCMV in malignancy.